The goal of Pyramid Solitaire is to remove all the cards from the Pyramid. The Pyramid or tableau consists of 28 face-up cards. You match cards that are in play based on being uncovered. At the start, all seven cards in the bottom row are uncovered. You can remove a card by matching cards that sum to 13 (Ace and Queen, 2 and Jack, 3 and 10, 4 and 9, etc.). When a King becomes uncovered, you can remove kings by themselves. You can deal cards from the deck to the discard and match those cards with the cards in the Pyramid. When you exhaust the deck, you can recycle the discard back into the deck. Matches: Ace and Queen, 2 and Jack, 3 and 10, 4 and 9, 5 and 8, 7 and 6.
A Pyramid Solitaire board consists of the Pyramid (or Tableau), the Done pile, the Deck, and the Discards. The Pyramid has 28 overlapping cards in 7 rows. A card is playable if it is not overlapped by cards in the row below it. You can remove cards to the Done pile if they are playable and their value sums to 13. Those cards are King by itself, Ace and Queen, 2 and Jack, 3 and 10, 4 and 9, 5 and 8, 6 and 7. The suits of the cards do not matter in Pyramid Solitaire. Cards in the deck can be dealt to the discard and placed face-up. The top card of the discard can match with playable cards from the Pyramid. You have won the game when all the cards of the Pyramid have been matched and removed.